(a) Fields of the Invention
The present invention relates to fabrication methods of a semiconductor device, and in particular to dicing methods thereof.
(b) Description of Related Art
Fabrication of a semiconductor device is typically made so that a great number of chips having various types of elements such as transistors are formed on a wafer and then dicing is performed to cut the wafer into chips. In thus performing a dicing, the wafer or the element may be broken to cause a decrease in the fabrication yield of the semiconductor device. For example, when blade dicing is performed, chipping sometimes occurs at the chip end. If this chipping reaches a region in the semiconductor device formed with the various types of elements such as transistors, the function of the semiconductor device is broken.
Various techniques for avoiding such breakage in dicing have been studied before.
As one example of the techniques, a semiconductor wafer dicing method disclosed in Japanese Patent No. 3500813 will now be described with reference to FIGS. 13A and 13B.
FIG. 13A shows a cross section of a portion of a semiconductor wafer 11. Although not particularly shown, the semiconductor wafer 11 is provided with chips having various types of elements. The wafer 11 is cut (diced) along a cutting line L in a scribe region R, thereby separating chips. The scribe region R is provided between the chips and used for dicing. In this cross section, in the scribe region R on the semiconductor wafer 11, insulating films 12 are provided on both sides of the cutting line L, respectively.
FIG. 13B shows how the semiconductor wafer 11 is being subjected to dicing by a blade 13. The dicing is performed along the cutting line L located between the two insulating films 12. During this dicing, even if the surface of the wafer 11 becomes chipped (a chipped shape 14 is created), the chipping is stopped by the insulating film 12. That is to say, the chipping is hindered from advancing more inwardly than the insulating film 12. Thus, the fabrication yield of the semiconductor device can be prevented from being degraded by chipping.